1. Field of the Invention
The present invention relates to a speed ratio control method for a continuously variable transmission, and more particularly to a speed ratio control method for a continuously variable transmission to optimally control a target engine speed in relation to an engine load.
2. Description of the Background Art
As a method of controlling a target engine speed in relation to an engine load, it is known to provide a plurality of maps for retrieving the target engine speed according to a throttle opening and correct a rate of shifting to the target engine speed according to a change in running condition (e.g., Japanese Patent Laid-open Publication No. 62-12430).
Although the rate of shifting of the target engine speed is corrected according to a change in running condition as in the above conventional method, it is difficult to properly control the target engine speed according to a driving condition only by retrieving the plural maps according to a throttle opening. Furthermore, in some cases, a change in engine load directly affects the behavior of a vehicle, and a desired drive feeling cannot accordingly be obtained.